Investigating the young stellar populations and hierarchies in nearby galaxies with the UVIT. II. Presenting the properties of 25,000 UV-detected star-forming clumps

arXiv:2606.12254 · astro-ph.GA · Submitted 2026-06-10 · Read on arXiv

astro-ph.GA

Submitted: 2026-06-10

Updated: 2026-09-10

Comments: Published in ApJS; Gairola Shashank et al, (2026) ApJS, 286, 38

DOI: 10.3847/1538-4365/ae9081

License: http://creativecommons.org/licenses/by-sa/4.0/

The gist: Studying young stellar populations within galaxies can help refine our understanding of recent star formation in galaxies and their evolution.

Terminology

Abstract

Studying young stellar populations within galaxies can help refine our understanding of recent star formation in galaxies and their evolution. With this motivation, we present a catalog of 25,000 recently formed (within 400 Myr) star-forming clumps (SFCs) in 17 morphologically diverse nearby galaxies, including 8 massive, classic spirals, 6 intermediate-mass, flocculent spirals, and 3 dwarf irregulars. We used far- and near-UV observations from the UltraViolet Imaging Telescope (UVIT), whose 1.5" angular resolution and 28' field-of-view allow us to probe SFCs at a mean physical scale of 54 parsec, within the full extent of our galaxies. We adopted a homogeneous SFC detection criterion, corrected for spatially varying dust attenuation (using 6" resolution A V maps, made by combining FUV with archival infrared observations), and estimated the SFC ages by comparing the observed UV color-magnitude diagrams with Starburst99 simple stellar population models. Using our SFC catalog, we studied the age demographic of the recently formed stellar populations across different galaxy morphologies and observed age trends consistent with several well-known phenomena, such as the inside-out formation of disc galaxies, local gravitational instabilities leading to flocculent spiral arms, and the stochastic nature of star formation in dwarf galaxies. Leveraging full galaxy coverage and FUV data, our catalog complements existing optically-identified star cluster catalogs in the literature towards improving our understanding of star formation across a wide range of galaxy morphologies, masses, and environments. We make the SFC catalog and A V maps of our 17 galaxies publicly available with this paper.

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